The drive for risk-based food safety management, systems and control has spread world-wide in
recent decades. Since the term is still internationally undefined, its use and implementation vary,
producing different realizations. In this Ph.D. thesis, microbiological risk assessment (MRA) was
investigated as a basis for risk-based food safety management, which was defined as ‘food safety
management based on risk assessment in order to achieve an appropriate level of protection
(ALOP)’. Governments are responsible for commissioning MRAs and also for setting food safety
targets up to a certain point, but the practical management measures that need to be in place in
order to achieve the targets are to be addressed by the operators. On the plant level, food safety is
usually managed through regulation, quality assurance systems and a hazard analysis and critical
control point (HACCP) programme with its prerequisites. In Finland, food safety management on
the food plant level is implemented through an HACCP-like regulated system termed an ownchecking
(OC) programme.
A quantitative microbiological risk assessment (QMRA) was conducted on salmonella in the beef
production chain according to the official standards of the Codex Alimentarius Commission
(Codex Alimentarius), and utilized in determining the food safety metrics for beef production. The
Finnish Salmonella Control Programme (FSCP) and the main official interventions due to it were
examined in the light of risk-based food safety management. The targets set for beef processing
plants by the government were converted into quantitative limits, and the results of salmonella
monitoring included in the FSCP were examined by the QMRA. The goal of the FSCP was
declared in 1994 to ‘maintain the present salmonella situation’, which was considered to refer to
the salmonella incidence in humans at that time, and also the de facto ALOP.
The requirement for a maximum salmonella prevalence of 1% at defined stages of the beef
production chain was embodied in the FSCP. This statement was considered to convey
performance objectives (PO) for the aforementioned stages. According to the QMRA, the de facto
ALOP was achieved in the referred year 1999, and even the true prevalence levels in the FSCP
were estimated to be clearly under the set PO limits with 95% credibility. However, the PO limits
were set too high for the de facto ALOP to be maintained in practice. If the salmonella prevalence
reached the PO limit of 1% or values near it, the public health risk would increase and overrun the de facto ALOP. The QMRA produced in this work has for the first time provided the possibility to quantitatively asses the relationships between targets set in the FSCP and their impact on public
health. At present, imports of beef and beef-derived foods may impose on Finnish consumers a
significantly greater exposure than domestic products. If their salmonella prevalence or their share
of the foods consumed in Finland increase, the number of human cases could rapidly rise.
The models for the QMRA were mainly Bayesian hierarchical models using Markov chain Monte
Carlo (MCMC) techniques, which was found to be a flexible and appropriate method for this type
of complex modelling. The resulting distributions were also regarded as an advantage compared to
the results from models developed with the deterministic approach, because the presentation of
results included the extent of the uncertainty, and also in this manner better illustrated the actual
operational environment.
Based on an inquiry, the personnel in food processing plants had a positive attitude towards food
safety management systems, but the knowledge, training and involvement of those employees
directly operating on the site with these systems were discovered to be deficient. Therefore, a
generic semi-quantitative hygiene risk assessment model, Hygram®, was developed for small and
medium-sized food enterprises to offer assistance in understanding, training, and, first of all,
detecting the critical steps of the processes, and thereby to contribute to the development of their
own-checking systems towards risk-based food safety management. Hygram® was not considered
a risk-based tool as such, but whenever the critical limits of the process have been defined as equal
to a risk assessment, Hygram® can be used as a risk-based management tool. It can also serve as a
tool for systematic hazard analysis and CCP detection when establishing a food safety
management system.
To conclude, the development of risk-based food safety management is a process in which risk
assessment is an essential tool. Scientific, technical, psychological and resource-bound barriers
need to be overcome in order to put risk-based management systems into practice. This study
showed that QMRA can be valuable in national risk management decision making, although few
QMRAs are currently available. Appropriate tools for practical risk management decision making
on the industrial level, such as Hygram®, need to be further developed.